Intake air box purpose/replacement.

[Skylarking]

There was a thread about this not very long ago, I can't remember who it was that posted up a heap of info from a company that developed their own intake but kept the expansion chambers because they enhance performance as well as decreasing intake noise. They were sprouting black magic like reversion wave technology and pressure equalization in intake velocity.

Personally, I believe it's just for noise reduction. How a reverted pressure wave (as opposed to a reverted "sound" wave) can overcome intake velocity as well as get past the throttle body is beyond my comprehension. This website had dynographs proving performance increases over straight pipe too, but we all know dyno results can never be manipulated to show a desired outcome.

Such “black magic” is talked about all the time regarding extractors and negative pressure waved bouncing back to the intake to suck just that little bit more gas out of the cylinder and aid performance... Everyone accepts that without question but when it’s the same physics used on the intake side to tune positive waves arriving at the intake ports, there are doubters

What I know from experience is that car manufacturers are cheap, sometimes real real cheap... and they play games...

As such, a straight or curved carry over pipe from an earlier model will always be cheaper to use than making a new injection mould for a complex shaped intake. So if they made it, there must be a strong reason and it must serve a purpose regardless of whether we understand it or consider it “black magic”.

Maybe that black magic is to make the car quiet so and optimise efficiency for the intake restriction that is the standard air filter. Maybe it’s simply to make it quiet to differentiate the refined cheaper models from the noisier performance models... who knows as what car makers use in their decision processes is where the real voodoo occurs... we are just their pin cushion dolls or fodder for their machine if you will

As to aesthetics of the WM, can’t any of the engine when the bonnet is closed, which is 99% of the time, so hardly worth the effort... Unless your the perspex panel with led fan type of PC owner

If OP wants power and noise, as mentioned, there are other better ways to accomplish such But doing so will devalue the WM in the longer term. At yhe end of the day the WM supposed to be a luxury car, it’s not a performance oriented and noisy machine

 

[lmoengnr]

Purely for noise, helps to lower the overall vehicle noise to comply with stationary/drive by noise limits.

 

[Not_An_Abba_Fan]

Such “black magic” is talked about all the time regarding extractors and negative pressure waved bouncing back to the intake to suck just that little bit more gas out of the cylinder and aid performance... Everyone accepts that without question but when it’s the same physics used on the intake side to tune positive waves arriving at the intake ports, there are doubters

What I know from experience is that car manufacturers are cheap, sometimes real real cheap... and they play games...

As such, a straight or curved carry over pipe from an earlier model will always be cheaper to use than making a new injection mould for a complex shaped intake. So if they made it, there must be a strong reason and it must serve a purpose regardless of whether we understand it or consider it “black magic”.

Maybe that black magic is to make the car quiet so and optimise efficiency for the intake restriction that is the standard air filter. Maybe it’s simply to make it quiet to differentiate the refined cheaper models from the noisier performance models... who knows as what car makers use in their decision processes is where the real voodoo occurs... we are just their pin cushion dolls or fodder for their machine if you will

As to aesthetics of the WM, can’t any of the engine when the bonnet is closed, which is 99% of the time, so hardly worth the effort... Unless your the perspex panel with led fan type of PC owner

If OP wants power and noise, as mentioned, there are other better ways to accomplish such But doing so will devalue the WM in the longer term. At yhe end of the day the WM supposed to be a luxury car, it’s not a performance oriented and noisy machine

Intake tuning and pressure waves are a real thing, within the intake manifold and head, just like the exhaust. Exhaust tuning takes place between the valve and the exhaust collector, these two points are most critical in getting scavenging right. Intake tuning takes place between the valve and the end of the intake runner, anything after the end of the intake runner is largely irrelevant. The plenum is there as a holding place for the next charge of intake air, beyond that, there is nothing that can be tuned (to a noticeable effect).

 

[Fu Manchu]

I recall Dad's Honda had it back in the '90's. The Honda Tech said it was for better throttle response.
It means there is a volume reserve of unused filtered air, when the throttle opens rapidly, that air is drawn in and some sort of improved response time is measured.

 

[Not_An_Abba_Fan]

I recall Dad's Honda had it back in the '90's. The Honda Tech said it was for better throttle response.
It means there is a volume reserve of unused filtered air, when the throttle opens rapidly, that air is drawn in and some sort of improved response time is measured.

Smoke and mirrors...

Any air that is in the intake tube between the filter and the TB is never "unused", it's ALWAYS being used, it's always moving. The nature of a 4 stroke multi cylinder engine, at least one cylinder is drawing air in at any given time. The pressure of the intake stream will always be less than atmospheric pressure.

What the Honda tech was probably confused with was plenum volume. The size of the plenum has a direct relationship to throttle response, as there is always an intake charge ready to be sucked into the intake runner. The cylinder is not waiting for the air to make its way from the throttle body.

 

[Fu Manchu]

It's pretty much it. Bare in mind I'm not an expert and the info I'm recalling is from 30 years ago. You explained it better than I ever could.

 

[Not_An_Abba_Fan]

Dealership techs are rarely experts themselves, just trained in the tech speak used by various brands.

 

[goldvn05]

Hi all , have VE Series 1 V6 LY7.

the plastic air intake box where it attaches to throttle body, that rubber bit with worm clamp on throttle body, is that replaceable ? (see pic)
mine has vacume leaks, throwing lean DTC codes on regular basis, did smoke test, and found large leak there, have seen second hand original air intake boxes on ebay, but also buying old plastic intake box with rubber so no garantees of good seal

any advise appreciated Thanks

 

[Fu Manchu]

Best bet is to get the intake pipe off eBay/market place etc. You won’t get them new.

 

[Fu Manchu]

You also have a leaking coolant filler cap.

Buy genuine. 140kPa